Methods for Regiocontrol in Polarized Polyene Systems

University Of Illinois At Chicago, Chicago IL

Investigators

Abstract

With the support of the Chemical Synthesis program in the Division of Chemistry, Justin Mohr of the University of Illinois at Chicago (UIC) is studying new techniques to control the nature of chemical transformations occurring from a class of versatile and readily generated intermediates called 'polarized polyenes.' The type of reactivity being explored complements established methods for organic synthesis and it is anticipated to streamline the manufacture of pharmaceutical agents, agrochemicals, and other useful advanced materials. In conjunction with catalyst discovery efforts, this research will target new strategies to precisely control the atomic connectivity and three-dimensional structure of complex products obtained from polarized polyenes. Crucially, and because these starting materials are capable of reacting in a variety of different ways, the research promises important fundamental advances in the area of divergent chemical pathways management. A demographically diverse group of undergraduate and graduate students within the Mohr laboratory will conduct the funded research. These individuals will gain valuable technical and scientific skills of relevance to potential future careers in the science, technology, engineering, and mathematics (STEM)-based workforce. The broader impacts of the project will include outreach activities conducted by the Mohr research team as they engage with Chicago-area K-12 students to promote science education. In addition, and to complement these and other ongoing efforts to broaden participation, Dr. Mohr actively recruits undergraduate students belonging to underrepresented groups to become involved in chemical research in his laboratory at UIC, a minority-serving institution (MSI). The development of efficient strategies for the assembly of polyfunctional molecules is facilitated by gaining new insights into the fundamental reactivity of progressively more complex intermediates. It is from this standpoint that the funded project focuses on the development of a suite of gamma-selective transformations from conjugated dienol systems [e.g., 1-(tert-butyldimethylsilyloxy)-1,3-cyclohexadiene], each example of which may provide a useful new synthetic tool for the elaboration of desirable target classes. Specific aims of the research include: (1) development of copper- and nickel-catalyzed stereoselective C–C bond forming reactions through examination of novel chiral ligand and chiral auxiliary designs, (2) expansion of metal-catalyzed coupling techniques to include problematic primary halide coupling partners, (3) examination of single-electron oxidation of dienol ethers to generate novel radical cation intermediates exhibiting regioselective reactivity, and (4) exploration of transition metal-catalyzed, site-selective C–heteroatom bond formation in polyene systems. Ultimately, the research is expected to help build a growing understanding of the basic factors that influence and control regio- and stereo-selectivity in polyene systems. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.